Improvement in malleable-iron castings



UNITED STATES PATENT OEEIcE.

JAMES E. ATWOOD, OF WORGESTER, MASSACHUSETTS.

IMPROVEMENT IN MALLEABLE-IRON CASTINGS.

Specification forming part of Letters Patent No. 221,996, dated November25, 1879 application filed November 12, 1878.

To all whom "it may concern:

Be it known that I, James E. ATwoon, of the city of Worcester, in thecounty of VVorcester and State of Massachusetts, have invented a new andImproved Mixture of Irons for White-Hearted Malleable-Iron Castings, ofwhich the following is a specification.

This invention has for its object to reduce the time, labor, and expenseof manufacturing malleable cast-iron, and to produce an improvedmalleable cast-iron, which may be distinguished from all other malleablecast-iron by its great density, which is nearly equal to that ofhammered cast-steel, and by its tensile strength, which is about doublethat of the ordinary malleable cast-iron; and, further, by its abilityto resist rust and receive a high polish, the facility with which it maybe casehardened, and the absence of all tendency to become laminated orthreaded or clawed up when being forged, like the ordinary malleableiron, during the operation of forging.

Heretot'ore malleable cast-iron has been produced by decarbonizing, to aproper extent, ordinary cast-iron, involving a process requirin g muchtime and labor.

By my improved process the amount of time and labor necessary to producethe iron is greatly diminished and a superior iron is produced.

To this end the invention consists in an improved white-heartedmalleable iron produced by mixing ordinary pig-iron and wrought-iron,either alone or in combination, with sprue, scoria, or dross, and fusingthe same together i and subjecting the mass to the action of theatmosphere, as more fully hereinafter specified.

The proportions of these materials may be varied considerably, accordingto the particular purpose for which the resultant product is to be usedbut for general purposes I have found that equal parts of carburet orpig iron and decarbonized or wrought iron answer well in practice withone part of sprue to every two parts of decarbonized iron. The materialsare properly mixed and placed in an ordinary reverberatory or othersuitable furnace, and maintained in a state of fusion for a propertimeaboutone hour and a quarter for one tonand subjecting it in themeantime to the influence of the atmosphere, by which the carbon isburned out to a proper extent, the product being a fine-grained and verydense iron, which may be readily cast, and is particularly adapted tothe manufacture of small articles, such as harness-mountings, buckles,carriage-wheel fenders, pistolframes, and the like, although it willanswer equally well for larger articles.

I am aware that wrought-iron and pigiron have'been combined by fusionfor the manufacture of steel, and this I do not claim; but

What I do claim is An article of manufacture consisting of awhite-hearted malleable iron possessing the density of hammered steeland a tensile strength of about double that of the ordinary malleableiron, as set forth.

JAMES E. ATWOOD.

Witnesses:

A. T. MATTHEWS, WLLLIAM BUCKLEY.

